Partition Effect of Coal and Quartz Particles in a Gas-Solids Fluidization Bed with Applied Electric Field

Electrostatic effects are commonly found in gas-solids fluidized bed. By applied electric field, the charged particles in fluidized bed would be separated according charge polarity. To investigate the feasibility of fine coal separation in a gas-solids fluidized bed with applied electric field, the binary particle mixture with 75% low ash coal and 25% quartz as a gauge mineral were used to explore the partition effect in a lab electric field fluidized bed unit. The particles in fluidized bed after fluidization were divided into seven sub products from negative slide to positive slide, and the yield and mass fraction of quartz in every product were analyzed. The influences of fluidization time, voltage applied to fluidized bed, fluidization velocity and static bed height on the partition effect were investigated. The results show that the mass fraction of quartz in the products decreases gradually from negative slide to positive slide. The increase of fluidization time, plate voltage and wind speed and the decrease of bed height are all beneficial to the improvement of enrichment effect, but the enrichment effect is no longer significantly improved when fluidization time is more than 15min. The mass fraction of quartz in the positive product is more than 40%, while in the negative product can be reduced to about 10%. The tests indicate that it is possible to separate fine coal by using a fluidized bed with applied electric field, and more research work is needed to conduct.